Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: question: Nomeie o presidente para iker casillas
 ###Tabelas: CREATE TABLE liverpool (liverpool_id AUTO_INCREMENT PRIMARY KEY, Round VARCHAR, Opposition VARCHAR, First leg VARCHAR, Second leg VARCHAR, Aggregate score VARCHAR) CREATE TABLE by_density (by_density_id AUTO_INCREMENT PRIMARY KEY, Rank VARCHAR, State VARCHAR, Population INT, Area (km²) INT, Density INT) CREATE TABLE general_information__&__feature_comparison (general_information__&__feature_comparison_id AUTO_INCREMENT PRIMARY KEY, Name VARCHAR, Year Began VARCHAR, s Registered user VARCHAR, Updated in past 30 days VARCHAR, Registration VARCHAR, Ability to syndicate off-site feeds VARCHAR, Userpics Free VARCHAR, Userpics Paid VARCHAR, Monthly Cost for Paid Account VARCHAR, Yearly Cost for Paid Account VARCHAR, Permanent Account VARCHAR) CREATE TABLE singles:_5_2–3 (singles:_5_2–3_id AUTO_INCREMENT PRIMARY KEY, Outcome VARCHAR, Date VARCHAR, Championship VARCHAR, Surface VARCHAR, Opponent in the final VARCHAR, Score in the final VARCHAR) CREATE TABLE personnel_and_sponsorship (personnel_and_sponsorship_id AUTO_INCREMENT PRIMARY KEY, Team VARCHAR, Chairman VARCHAR, Head Coach VARCHAR, Captain VARCHAR, Kitmaker VARCHAR, Shirt sponsor VARCHAR)  
SELECT Chairman FROM personnel_and_sponsorship WHERE Captain = Iker Casillas